Westborough leans heavily Democratic by roughly 40 points: about 70% of voters vote Democratic and 30% Republican.
About 51% of adults in Westborough typically vote, below the U.S. average of about 62%. Among adults in Westborough, ~36% vote Democratic, ~15% Republican, and ~49% don't vote. The map below shows estimated turnout by block group.
How Westborough compares
Among neighborhoods within 5 miles, Westborough leans more Democratic than 10 of 19 neighbors.
Westborough runs about 21 points more Democratic than California as a whole.
Why Westborough leans the way it does
This analysis examined 14,881 data points per neighborhood to find what predicts political lean and turnout. The items below are a few correlations that stood out for Westborough, not a ranked or complete list of what matters most.
Dense areas vote Democratic. More than 99% of residents in Westborough live in densely developed areas, about 64 points above the U.S. average of 36%.
Population density and Democratic lean
Places with high population density tend to lean Democratic; Westborough, South San Francisco, CA sits in the top tenth nationally on this measure.
Why turnout in Westborough looks the way it does
Crowded housing lines up with lower turnout. About 10% of homes in Westborough have more than one occupant per room, above 91% of neighborhoods. Learn more about the findings and methodology on the political spectrum map.
Nearby Neighborhoods
- Serra Highlands, South San Francisco, CA D+43
- El Camino, South San Francisco, CA D+43
- Westview, Pacifica, CA D+52
- Serramonte, Daly City, CA D+36
- Sunshine Gardens, South San Francisco, CA D+41
- Fairmont, Pacifica, CA D+38
- Sharp Park, Pacifica, CA D+51
- Edgemar-Pacific Manor, Pacifica, CA D+54
- Lindenville, South San Francisco, CA D+40
- Downtown South San Francisco, South San Francisco, CA D+46
Neighborhoods with Similar Populations
- Land Park, Sacramento, CA D+63
- Deep Creek West, Chesapeake, VA D+5
- Beechhurst, Queens, NY R+20
- Airport, Detroit, MI D+57
- Hartford, Providence, RI D+29
- Adams Crossroads, Duluth, GA D+28
- East Central Westminster, Westminster, CO D+18
- SouthWest Anaheim, Anaheim, CA D+11
- Westlake Village Area-Los Angeles, Westlake Village, CA D+13
- Belmont Shore, Long Beach, CA D+48
Sources and methodology
Precinct-level voting records used to fit the model come from California Secretary of State, Elections, distributed by the Voting and Election Science Team. Demographic inputs come from the U.S. Census Bureau (ACS 5-year estimates and the 2020 Decennial Census). Health and environmental inputs come from the CDC (PLACES and the Environmental Justice Index). Land cover comes from the USGS and EPA. Election-day and lead-up weather come from PRISM 4km daily grids and the NOAA Global Historical Climatology Network. Mail-voting and election-administration patterns come from the MIT Election Lab's Survey of the Performance of American Elections. Block-group crime detail comes from CrimeGrade. Internet data and modeling support provided by ISPreports.org.
Modeling and analysis by the BestNeighborhood data science team. Full methodology and findings: political spectrum map.
Methodology reviewed by the BestNeighborhood data team. Last updated May 2026.